You add users to the roles by navigating to the item you wish to secure. You then click on the property tab, then the security sub-tab. From here you can click on 'New Role Assignment'. Now you can add a user or group and assign the role you wish for them to have on this item.
You can also do this at the site level for the site level permissions. Click on 'Site Settings' in the upper right hand corner. Then click on 'Configure site-wide security'. From here you can again add users and assign them different system roles.
-Daniel
Help with roles in SQL Server Reporting Services 2005
Help with roles in SQL Server Reporting Services 2005
JakeG1018
You can also do this at the site level for the site level permissions. Click on 'Site Settings' in the upper right hand corner. Then click on 'Configure site-wide security'. From here you can again add users and assign them different system roles.
-Daniel